IQ test scores have risen steadily across the industrialized world ever since such tests were first widely administered, a phenomenon known as the Flynn effect. Although the effect was documented more than 2 decades ago, there is currently no generally agreed-on explanation for it. The author argues that the phenomenon heterosis represents the most likely cause. Heterosis, often referred to as ...

SE of hybrid vigor is of great importance in terms of present-day agricultural production. For example GARDNER (1968) states: ". . . Development and use of heterosis has been the most important practical achievement of genetics so far. The monetary value of the increase in corn production due to use of heterosis for a single year has been estimated to exceed the total cost of federal research f...

Heterosis, the evident superiority of a hybrid to its parents, has not been defined in precise genetic terms. The reasons given for heterosis are for the most part rather general and vague. A recent statement is made that heterosis is the phenotypic result of gene interaction and occurs because the heterozygote either masks different detrimental recessive genes which are homozygous in the paren...

Quantifying the importance of random genetic drift in natural populations is central to understanding the potential limits to natural selection. One approach is to estimate the magnitude of heterosis, the increased fitness of progeny derived from crosses between populations relative to crosses within populations caused by the heterozygous masking of deleterious recessive or nearly recessive all...

The advancement in microarray technology enables the simultaneous measurement of expression levels of thousands of genes. However, due to the relatively high cost of making a replicate in a microarray experiment, the number of replicates in a single experiment is typically small. This results in the “small n, large p” problem for statistical inferences, where there are gene expression measureme...

This study was conducted to produce a high percentage of genetically male tilapia through interspecific hybridization between Nile tilapia, Oreochromis niloticus and Blue tilapia, O. aureus and evaluate sex ratio, productive performance and heterosis of the progeny produced. The results revealed that sex ratios of the progenies of (♀ O. aureus x ♂ O. niloticus) and (♀ O. niloticus x ♂ O. aureus...

The primary objective was to estimate breed, heterosis, and recombination effects on growth and carcass traits of two different four-breed composite populations of pigs. Experiment 1 (Exp. 1) included purebred and crossbred pigs originating from Yorkshire, Landrace, Large White, and Chester White breeds, and Experiment 2 (Exp. 2) included pigs from Duroc, Hampshire, Pietrain, and Spot breeds. D...

This study was conducted to produce a high percentage of genetically male tilapia through interspecific hybridization between Nile tilapia, Oreochromis niloticus and Blue tilapia, O. aureus and evaluate sex ratio, productive performance and heterosis of the progeny produced. The results revealed that sex ratios of the progenies of (♀ O. aureus x ♂ O. niloticus) and (♀ O. niloticus x ♂ O. aureus...